sensors Mode-S transponder

4BA999

ICAO 24-bit transponder address · allocated to Turkey

Currently assigned to TC-JLY · AIRBUS A-319

Hex
4BA999
Octal
22724631
Decimal
4,958,617
Country
TR
Tail
TC-JLY
Type
A319
No current signal · last broadcast 1h ago
Flights observed
6
Distinct callsigns
6
Country
TR
Last broadcast
1h ago

Last known position

Most recent position reported by Mode-S 4BA999.

Country allocation

The ICAO 24-bit address 4BA999 falls within the block assigned to Turkey (TR) by ICAO Annex 10, Volume III. Every aircraft registered in Turkey receives a permanent address from this block at the time of registration; the address stays with the airframe even if the aircraft is re-registered to a different operator within the country.

Callsign history 6 distinct

Callsign Airline Flights Last seen
THY87R - 1 2026-05-09
THY6YS Turkish Airlines 1 2026-05-11
THY6FE Turkish Airlines 1 2026-05-11
THY5KB Turkish Airlines 1 2026-05-09
THY49F - 1 2026-05-11
THY2TX Turkish Airlines 1 2026-05-08

Recent flights last 6

DateFlightRouteTakeoffLandingDuration
2026-05-11 THY49F - May 11, 12:50 UTCMay 11, 13:10 UTC20m
2026-05-11 THY6YS TLL → IST May 11, 11:10 UTCMay 11, 11:40 UTC30m
2026-05-11 THY6FE IGD → IST May 11, 04:05 UTCMay 11, 07:50 UTC3h 45m
2026-05-09 THY5KB IST → VNO May 9, 17:25 UTCMay 10, 06:00 UTC12h 35m
2026-05-09 THY87R - May 9, 15:35 UTCMay 9, 16:05 UTC30m
2026-05-08 THY2TX IST → AMS May 8, 11:09 UTCMay 8, 11:19 UTC10m

About Mode-S

A Mode-S transponder code (also called an "ICAO 24-bit address" or "hex code") is a 6-character hexadecimal identifier permanently assigned to an aircraft when it's first registered. Unlike callsigns (which change with each flight) or registrations (which can change if an aircraft is sold internationally), the Mode-S address stays with the airframe for the life of the aircraft in that country.

Every ADS-B transmission from an aircraft includes its Mode-S address, making it the most reliable way to identify a specific airframe. Flight-tracking services like Apparatus use the Mode-S address as the primary key for tying position broadcasts, callsigns, and ownership records together.

Prefer a tail-number view? See the TC-JLY page for operator, model, and routing details .

Mode-S 4BA999 frequently asked

What is Mode-S code 4BA999?
4BA999 is an ICAO 24-bit transponder address. Allocated to Turkey. Assigned to TC-JLY.
Where is Mode-S 4BA999 registered?
Mode-S code 4BA999 is allocated to Turkey (TR). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4BA999 broadcasting right now?
No active broadcast right now. Last signal was 1h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4BA999, octal 22724631, decimal 4,958,617.
What flights does 4BA999 operate?
Mode-S 4BA999 has broadcast 6 distinct callsigns, including THY87R, THY6YS, THY6FE, THY5KB, THY49F.